Naslov
Influence of catchment urbanisation on the consumption patterns and structure of temperate, low-order stream food webs

Autori
Price, Elliott Laurence

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, diplomski rad, diplomski

Fakultet
School of Biological & Chemical Sciences

Mjesto
London

Datum
30.09

Godina
2017

Stranica
45

Mentor
Kratina, Pavel ; Sertić Perić, Mirela

Ključne riječi
diet estimates ; aquatic macroinvertebrates ; stable isotope analysis ; trophic interactions ; urban streams

Sažetak
The chemical and physical characteristics of streams are changing in response to the urbanisation of their catchment. These altered conditions are likely to influence the flow of energy, and the composition and source (i.e. terrestrial/aquatic) of nutrients that are available to the constituents of associated aquatic food webs. The exact nature of the effects of catchment urbanisation on the abundance, diversity and function of stream macroinvertebrates, as well as on the structure and interactions of stream food webs, is currently unknown. To identify these patterns, we constructed mixing models and isotopic-niche plots with stable isotope ratios of 12C/13C and 14N/15N in whole-body macroinvertebrate tissues and basal resource materials to compare the structure of food webs and macroinvertebrate consumer patterns in relation to the abiotic characteristics of six urbanised sites, four agricultural sites and five woodland sites along an increasing urban gradient of five streams in the region of Zagreb, Croatia. Urbanised sites had lower trophic redundancy with fewer interactions between trophic levels, indicating a more fragile system. High δ15N values of macroinvertebrates were observed in urbanised sites relative to woodland and agricultural sites in all functional feeding groups analysed. Higher nitrates promoted the contribution of macrophytes to herbivore diets, and phosphorous inputs promoted a shift in a diatom-based to a filamentous algae-based periphyton community. The contribution of terrestrial sources to the energy and nutrient requirements of the stream ecosystems remained largely constant. Although predator diets were able to track changes in the abundance of functional feeding groups, it is concluded that urbanised catchments alter the base of the food web, which induces a trophic cascade that destabilises the structure by changing the number of trophic interactions and the shifting the dietary resources available to macroinvertebrates.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Interdisciplinarne prirodne znanosti

Napomena
Student je diplomirao na Queen Mary University of London, School of Biological & Chemical Sciences, London, UK

POVEZANOST RADA